Electronic devices, such as personal computers, are provided with docking connectors that connect the electronic device to an extension unit. High-density, compact docking connectors having numerous contacts have been developed to increase the performance and networking of the electronic devices. Because of the high density of these docking connectors, it is important that mating connectors in the docking connector are accurately positioned so that all of the corresponding contacts contact each other.
A first example of a docking connector that aligns corresponding contacts to each other is illustrated in JP 11-288760 and shown in FIG. 16. The docking connector 101 includes a first connector 110 that mates with a second connector 120. The first connector 110 is mounted on a first circuit board PCB1 that is provided on a side of a personal computer (not shown). The first connector 110 comprises an insulating first housing 111 and a plurality of contacts 112. A pair of guide pins 113 extends from a mating surface of the first connector 110 and are provided on ends of the first housing 111. The guide pins 113 are constructed so that the guide pin on one end has a larger diameter than the guide pin on the other end. The guide pins 113 are attached to the first housing 111 by attachment fittings 114 that are attached to the first housing 111.
The second connector 120 is mounted on a second circuit board PCB2 provided on a side of an extension unit (not shown). The second connector 120 comprises an insulating second housing 121 and a plurality of contacts 122. A pair of guide members 123 that receive the guide pin 113 of the first connector 110 are provided on each end of the second housing 121. The guide members 123 are attached to the second housing 121 by attachment fittings 124 that are attached to the second housing 121. At the time of mating the first connector 110 and the second connector 120, the guide pins 113 are inserted into the guide members 123. The positional deviation between the first connector 110 and the second connector 120 is absorbed, and it is possible to correctly align all of the contacts 112, 122 with each other.
In the docking connector 101 shown in FIG. 16, the docking connector 101 is for use in right-angle connections so mating surfaces of the first circuit board PCB1 and the first connector 110 and mating surfaces of the second circuit board PCB2 and the second connector 120 are perpendicular. Accordingly, the docking connector 110 is not suitable for applications requiring the mating surfaces of the first circuit board PCB1 and the first connector 110 and the mating surfaces of the second circuit board PCB2 and the second connector 120 to be parallel.
An example of an electrical connector that aligns corresponding contacts to each other is illustrated in JP 8-315910 and shown in FIG. 17. The electrical connector 201 consists of a first connector 210 that mates with a second connector 220. The first connector 210 is mounted on a side of a first circuit board PCB1. The first connector 210 comprises an insulating first housing 211 and a plurality of contacts 212. A pair of guide pins 213 extends from a mating surface of the first connector 210 at ends of the first housing 211.
The second connector 220 is mounted on a side of a second circuit board PCB2 that is substantially parallel to the first circuit board PCB1. The second connector 220 comprises an insulating second housing 221 and a plurality of contacts 222. A pair of accommodating recessed members 223 into which the guide pins 213 of the first connector 210 are inserted are formed in ends of the second housing 221. When the first connector 210 and the second connector 220 are mated, the guide pins 213 are inserted into the accommodating recessed members 223 so that positional deviation between the first connector 210 and the second connector 220 is absorbed, and it is possible to align all of the contacts 212, 222 with each other.
In the electrical connector 201 shown in FIG. 17, mating surfaces of the first circuit board PCB1 and the first connector 210 and the mating surfaces of second circuit board PCB2 and the second connector 220 are parallel. However, the guide pins 213 of the first connector 210 are accommodated inside the accommodating recessed members 223 in the second connector 220 when the first connector 210 is mated with the second connector 220. Accordingly, the electrical connector 201 can not be formed with a low height. If the length of the guide pins 213 is shortened in order to lower the height, adequate guiding function can not be achieved. Additionally, forming openings in the second circuit board PCB2 for receiving the guide pins 213 will not effectively reduce the height, because wiring or the like is not possible in the openings, so the electrical connector 201 will not be suitable for high-density mounting.
Another example of a docking connector for connecting a personal computer and an extension unit is illustrated in JP 2000-089850 and shown in FIGS. 18–19. The docking connector comprises a first connector 302 and a second connector 311. The first connector 302 is provided on a circuit board 303 on a side of a personal computer 301. The second connector 311 is provided on a side of an extension unit 310 and mates with the first connector 302. Guide pins 312 that guide the first connector 302 and the second connector 311 to the docking position are provided on the extension unit 310. The guide pins 312 extend from an upper housing 310a of the extension unit 310 and allow vertical movement of the guide pins 312. The guide pins 312 are biased upward by springs 314.
A groove 312a is formed in an outer circumference of each of the guide pin 312. A substantially U-shaped release spring 316 is received in the groove 312a. An attachment fitting 318 that restricts the downward movement of the U-shaped release spring 316 is attached to the upper housing 310a by a screw 319. A release pin 315 that releases the U-shaped release spring 316 from the groove 312a is attached thereto so that the release pin 315 can move in an up and down direction. Each of the release pins 315 is constantly biased upward by a spring 317. A bottom portion of the extension unit 310 is provided with a lower housing 310b. Grounding fittings 313 that contact the guide pins 312 when the guide pins 312 are lowered are provided on the lower housing 310b. 
When the first connector 302 and the second connector 311 are mated, the guide pins 312 of the extension unit 310 enter the guide pin receiving openings 304 in the personal computer 301. Upper ends of the release pins 315 contact a bottom surface of the personal computer 301. Since the U-shaped release springs 316 are received in the grooves 312a in the guide pins 312, the downward movement of the guide pins 312 is restricted by the U-shaped release springs 316. When the personal computer 301 is moved further downward, the U-shaped release springs 316 are spread apart by the release pins 315 in a direction of the plate surface of the attachment fittings 318 so that the U-shaped release springs 316 are released from the grooves 312a. As a result, downward movement of the guide pins 312 is made possible. When the personal computer 301 is moved further downward, the guide pins 312 contact the grounding fittings 313, and the first connector 302 and the second connector 311 are fully mated.
In the docking connector shown in FIGS. 18–19, the guide pins 312, the U-shaped release springs 316, the attachment fittings 318, the release pins 315, and the springs 317 that lock and unlock the vertical movement of the guide pins 312 are provided in the extension unit 310 separate from the second connector 311. Space inside the extension unit 310 is therefore required, which reduces space in the extension unit 310 for other components and limits design options. Moreover, the mechanism that allows the vertical movement of the guide pins 312 and the mechanism that locks and unlocks the vertical movement of the guide pins 312 is complex, which increases manufacturing costs.